Liquid-fuel vaporizer



Oct. 23 1923'.

1,471,470 G. KEITH ET AL LIQUID FUEL VAPORI ZER Filed May 6, 1922 Patented Get. 23, i923.

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enonen KEITH Ann wrtrnnn aunnosnwnarivrcuen; or Lennon, ENGLAND.

LIQUID-FUEL varonrzn'n.

Application filed May a,

new and useful Improvement in Liquid-Fuel Vaporizers, of which the following is a specification.

This invention relates to a liquid fuel va porizer device adapted particularly for use in conjunction with means for controlling the supply of mixture to internal combustion engines as described, for example, in the specification of Letters Patent No. 1,317,709.

In the use of a vaporizer in connection with such automatic controlling means three problems have called for solution; firstly, the problem of rendering the vaporizer itself sufficiently flexible in capacity to meet widely varying demands and at the same time capable of dealing with fuels'of a comparatively high boiling point; secondly, the elimination of the trouble of hunting; and thirdly, the prevention'of flooding of the vaporizerandgovernor with liquid fuel in the event of the vaporizer not being hot enough to vaporize it or convert it into gas.

The requirement are answered by the device hereinafter described and illustrated 'diagrammatically in vertical section in the accompanying drawin The vaporizer is adapted to be heated by the exhaust gases and includes a metallic heat exchanger structure having an inlet connection A for the exhaust gases located above a partition 13 having an aperture (3 through which the gases pass downwards, the partition B resting on a series of staggered metallic pins C or the like between which the gases pass in sinuous streams, and

having a second aperture Z) through which the gases flow upwards again to issue through an outlet connection D. This direction of flow of the gases is denoted by the line J3U on the drawing. The pins C uprise from a metallic plate E from which depends a solid portion F which dips into the liquid fueland through which are formed a number of vertical sawcuts 2 interconnected at the upper end by a port Gr whence a pipe H passing through the apertured partition B carries off the vapor. A stop valve J controls the upward flowbf vapor.

The solid portion F is surrounded by a cup K enveloped by lagging and having at 1 922. Serial No. 559,036.

thelower end an extension K" which is fitted with some: material'of fairly good thermal conductivity and presenting a large surface, suchas a suitable metal a 1n granulated form, or in the form of cuttings or other particles, with a layer L of wire gauze sepa rating this material from the solid depend;

ing portion F.

The fuel'is fed into the lowe'rend of the extension K. throu h a hollow plug M provided .with fine savi -slits.

The above described arrangement permits the maximum extraction of heat from the exhaust gases without interposing too high a resistance, and the transference of this heat to the liquid in such wise as to insure a progressive'action .both as regards tem perature change and area of surface.

The solid portion F will evidentlybecome progressively cooler towards the bottom end,

partly due to slu'ggishness in conductivity and partly due tothe cooling effect of coiv tact with the colder liquid; This circum'; stance by itself is not sufficient to prevent the sudden flashing into vapor of the lighter.

fractions of the fuel on occasion, for which reason the extension K is not surrounded by lagging so that it may become comparatively cool towards its lowerend.

saw-cuts 2 in the portion F presents a rapidly increasing heating surface to the fuel with a comparatively small increase in the bulk of the fuel, so that upon a sudden demandfor gas no time is lost in heating up thefuel,

I B5 It will be seen that the large area of the.

outlet H of the vaporizer, and, if no provision were made to prevent it, it would be posible to pull the fuel in liquid form through the vaporizer should there be insuilicient heat to vaporize it. A fuel cup N having a float chamber is therefore located at some point outside the vaporizer at such a height that when the'fioat valve .closes the fuel does -not rise above the level shown by the dotted line. This level is unaffected the suction, as the float chamber is placed in balance by means of a pipe 0 connecting the top of the chamber N with the upper part of the vaporizer and a pipe 0 connecting the lower part of the said chamber to the bottom of the vaporizer. The float P is pref cuts off communication between the float chamber in the fuel cup N and the fuel supply R to a fuel tank. 7 In the event of the float chamber and vaporizer being filled up with liquid when cold, and of the float operated valve Q being closed in consequence, with the stop valve J also closed, when the vaporizer begins to heat up, it would be possible to create a dangerous pressure within it. To obviate this thearea of the valve Q is so chosen in proportion to the size of the float P that, should the pressure within the vaporizer rise more than a few pounds tot-he square inch, this pressure will overcome the lifting power of the float P and open the valve Q, permitting the liquidcontained in the vaporizer and float chamberto beblown back into the fuel supply tank through the pipe R until it is out of range of the heating elements in the vaorizer.

lVith this arangement the fuel admission to the vaporizer may be left permanently open, it being only necessary to open or shut the stop valve J to put the vaporizer 1n or out of action.

1. A liquid fuel vaporizer for internal combustionengines arranged to be heated by the exhaust gases of the engine, cornprising a metallic heat exchanger adapted to be partly immersed in the liquid fuel and presenting on its upper side a large surface for. contact with the gases, said heat exchanger being constructed to divide the gases into sinuous streams and with an insent a large liquid contact surface, a float chamber, a liquid fuel supply connection to said float chamber, a connection from the lower end of said float chamber to said heat exchanger-and a connection fromthe upper end of saidfloat chamber to said heat 6X- changer.

, 2. A liquid fuel vaporizer arranged to be heated by the exhaust gases including a heat-exchanging element comprising a metallic plate having, 011 its upper side, pins between which the gases pass and having on the under side a solid portion intersected by cuts interconnected by a port and presentlng a liquid contact surface, and a metallic substance in the form of particles contiguous with said solid portion.

3. A liquid fuel vaporizer, arranged'to be heatedv by the exhaust gases, including a heat-eXchanging element comprising a metallic plate having on its upper side staggered pins between which the gases pass and having on its under side a solid portion intersected by cuts interconnected by a port and presenting a liquid contact surface, a connection for leading exhaust gases to the upper side of said plate, a connection for leading liquid fuel to the lower side of said. plate, and a connection to said port for lead ing 01f vaporized fuel.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

GEORGE KElTH. WILFRED AMBROSE WHATI'IIOUGl-l.

Witnesses ISABEL RoLLo,

KATE /VOTHERINGHAM. 

